The Effect of HLA and Insulin‐Dependent Diabetes Mellitus on the Secretion Levels of Tumour Necrosis Factors Alpha and Beta and Gamma Interferon

Abstract

Tumour necrosis factors alpha and beta (TNF-α and TNF-β) and gamma interferon (IFN-γ) were measured by ELISA in the supernatants of phytohaemagglutinin (PHA)-activated peripheral blood mononuclear cells (PBMNC) from 98 individuals (60 controls and 38 patients with insulin-dependent diabetes mellitus [IDDM]. The PBMNC were incubated with varying concentrations of PHA (0,1,5, and 10 μg/ml) for 72 h. In our population study we observed a correlation between the levels of secretion of TNF-α and IFN-γ but not TNF-β. The complete data set was analysed by non-parametric tests, and no associations with HLA phenotypes existed. Reduced levels of TNF-β, but not TNF-α or IFN-γ, secretion were found in IDDM patients stimulated with 1 and 5 μg/ml of PHA (P -0.001 and 0.02 respectively). None of the lymphokine secretion levels at any PHA concentration correlated with particular HLA phenotypes. Analysis of the natural log-transformed data indicated that only for the TNF-β levels (at 5 μg/ml PHA) could subjects be divided into high and low secretors, which also did not correlate with a particular HLA-B or -DR antigen.